Clinical burden and healthcare resource use of congenital thrombotic thrombocytopenic purpura in England: A linked primary and secondary care data analysis

Congenital thrombotic thrombocytopenic purpura (cTTP) is an ultra rare haematological disorder. This study aimed to estimate the clinical burden, healthcare resource use (HCRU) and associated costs of cTTP in England using primary and secondary care data. A retrospective cohort study was undertaken using the Clinical Practice Research Datalink (Aurum) linked to Hospital Episode Statistics data. The study period was from 01 January 2000 to 31 December 2019. Patients with cTTP were identified using an algorithm and matched 1:2 to patients without thrombotic thrombocytopenic purpura (TTP) (non-TTP cohort) to contextualise the findings. A total of 36 cTTP patients were identified. The mean follow-up for cTTP patients was 4.4 and 5.7 years in primary and secondary care, respectively, and 4.9 and 5.8 years for the non-TTP cohort. Of the 36 patients, 38.9% experienced an acute episode and 19.4% experienced an organ damage event during follow-up. HCRU (including inpatient admission, outpatient appointments and primary care appointments) was higher in the cTTP cohort relative to the non-TTP cohort. The average yearly cost of healthcare for a cTTP patient was £6155, relative to £858 in the non-TTP cohort. This study demonstrates the high clinical and economic burden of cTTP and provides evidence to inform healthcare planning.